This invention relates to apparatus and method for drawing or for drawing and ironing a workpiece. More particularly, the invention relates to apparatus and method for lubricating and cooling a workpiece and an ironing ring or die in a press as the workpiece is worked within the ring or die.
The principal method of making can bodies for the carbonated beverage market is to draw and iron the bodies from a circular metal blank. A typical can body is made by blanking, drawing the blank into a shallow cup, and then forcing the cup directly through two or more ironing dies to thin and lengthen the sidewall. The blank is usually first drawn into a cup with a draw press, and thereafter the cup is redrawn and ironed with a redraw and ironing press, commonly referred to as a bodymaker.
In ironing the sidewall of the cup to thin and lengthen it, the metal is severely worked as it passes through at least two or more ironing rings or dies. Bodymakers operate at very high speeds to produce economically the volume of can bodies required to satisfy the market.
To minimize the amount of heat generated in the workpiece and tooling as an effect of such severe, high speed forming, and to minimize stresses in the sidewall from friction with the ironing ring, it is necessary to flood or bathe the tooling and workpiece with a lubricant and coolant. Without proper lubrication and cooling, the workpiece becomes distorted. It may fracture, or the tools may become damaged by metal pickup or metal transfer, for example, from the workpiece.
Heretofore, the workpiece and tooling have been cooled and lubricated with lubricant and coolant mixtures which include lubricants distributed to the tooling or workpiece in a variety of ways. U.S. Pats. Paramonoff 3,735,629, Maeder 4,148,208, and Main 4,223,544 are patents which disclose in whole apparatus for distributing lubricant and coolant in a drawing and ironing press. Although effective systems have been developed for lubricating bodymakers, problems still arise which affect productivity, waste disposal, cost of washing can bodies, can quality, and flavor of the packaged product.
There is a need, therefore, for improved methods and apparatus for lubricating and cooling for drawing and ironing metal articles.